Series Array Research Articles

Spectral Response of Arrays of Half-wave and Electrically Small Antennas with SINIS Bolometers

Two types arrays of annular half-wave and electrically small antennas with typical sizes of the elements corresponding to 1/10 of the wavelength at SubTHz band with integrated superconductor-insulator-normal metal-insulator-superconductor (SINIS) bolometers have been developed, fabricated and experimentally studied. We performed numerical modeling of the full structure and use additional reference channels in experimental studies to enhance the accuracy of the spectral response estimations of receiving arrays. In experiments three reference channels were used for normalization of the spectral response: a pyroelectric detector outside the cryostat, and two cold channels-a RuO(2)bolometer and on-chip thermometer comprising series array of NIS-junctions.

Integrated Discretely Tunable Optical Delay Line Based on Step-Chirped Subwavelength Grating Waveguide Bragg Gratings

We demonstrate experimentally a discretely tunable optical delay line (ODL) using a step-chirped subwavelength grating (SWG) waveguide Bragg grating (BG) in silicon-on-insulator (SOI). The step-chirped structure is implemented using a serial array of 10 SWG waveguide BGs. It is designed using 3D finite-difference time-domain (FDTD) and the transfer matrix method (TMM), and is fabricated using electron beam lithography with a single etch. The grating structure has a total time delay of ∼60 ps in steps of ∼6.6 ps over an operating bandwidth of 41.7 nm; the measured results are in good agreement with simulations. We demonstrate the application of the ODL for antenna beamforming in simulations; in particular, we calculate the array factors for different phased array antennas using the measured time delays.

Parametric recurrence quantification analysis of autoregressive processes for pattern recognition in multichannel electroencephalographic data

Recurrence quantification analysis (RQA) is an acknowledged method for the characterization of experimental time series. We propose a parametric version of RQA, pRQA, allowing a fast processing of spatial arrays of time series, once each is modeled by an autoregressive stochastic process. This method relies on the analytical derivation of asymptotic expressions for five current RQA measures as a function of the model parameters. By avoiding the construction of the recurrence plot of the time series, pRQA is computationally efficient. As a proof of principle, we apply pRQA to pattern recognition in multichannel electroencephalographic (EEG) data from a patient with a brain tumor.

Infrared pixel based on Seebeck nanoantennas

AbstractBolometric arrays dominate in commercial terahertz and millimeter wave imagers. Bolometers tend to be slow and require an operating bias that increases the power budget. This paper presents first results on antenna-coupled thermo-electric junction detectors, a potentially attractive alternative to microbolometers. The nanoscale junctions have small thermal mass and can be much faster than bolometers. These junctions are heated by currents excited in spectrally-selective antennas and generate a voltage based on the Seebeck effect without any externally applied power. A pixel comprising a series array of antenna coupled junctions with peak response at 7.5 THz (40 μm wavelength) is designed and experimentally demonstrated. Responsivity of 5 MV/W, 500 Hz chopping frequency, and D* of 3.5 x 1010 Jones are demonstrated.

Conditioning of Superconductive Properties in Graph-Shaped Reticles

We report on phenomena observed in planar integrated networks obtained connecting superconducting island by Josephson tunnel junctions. These networks, identifiable as tree-like graphs, have branches consisting of series arrays of Josephson junctions which can be individually current biased and characterized. Both Josephson supercurrents and gap parameters of the arrays embedded in the graph structures display properties significantly different from those of “reference” arrays fabricated on the same chips and having identical geometrical shape. The temperature and magnetic field dependencies of the Josephson current of the embedded arrays both show a singular behavior when a critical value is reached by the Josephson characteristic energy. The gap parameter of the junctions generating the embedded arrays is higher than that of the junctions forming the reference geometrical arrays.

Cascade GaN-based blue micro-light-emitting diodes for dual function of illumination and visible light communication

The dual function of illumination and visible light communication is a promising solution for a low-cost high-speed wireless access network. To realize high optical power and large modulation bandwidth, the cascade GaN-based top-emitting blue micro-light-emitting diode array chips are proposed. The electrical, optical, and communication performances of the series or parallel array chips with 1, 4, and 10 pixels are characterized and discussed. With increasing the number of pixels, the series configuration gives a high-voltage chip, while the parallel configuration under the same current density gives a high-current chip, in which the significantly increased flowing current causes the increased heat thereby reduces the allowable maximum current density and amplitude of the modulation voltage signals. Either series or parallel array is an efficient way to improve the optical powers. However, the average light-output powers (LOPs) and average external quantum efficiencies (EQEs) per each pixel decrease as the number of pixels increases, owing to the light absorption by adjacent pixels and the increased heat effect. Furthermore, with increasing the number of pixels, the modulation bandwidths, the bit-error rates (BERs), and the maximum data rates in series configuration are improved, while those in parallel configuration are deteriorated. Comparing to the parallel counterpart, the series configuration is preferred in the dual function system, because of its higher allowable current densities, LOPs, EQEs, and modulation bandwidths, as well as lower BERs and larger maximum data rates. The improved performance can be attributed to the reduced heats and the decreased device capacitances in the series array chips.

Possible dynamics of Josephson junction arrays connected to high-Q tank circuit

Serial Josephson junction arrays connected to high-Q tank circuit are analysed and discussed. Numerical simulation of the systems shows two possible oscillation modes above resonance frequency when the tank impedance is capacitive. These are the inphase oscillation mode and the collectively antiphase oscillation mode. This fact is responsible for complicate switching dynamics, which can block parametric resonance excitation. Stability domains of the modes depend on McCumber parameter of the junctions. Increase in this parameter is favourable to the inphase mode. When the inphased oscillations are feasible, the resonance peak-like peculiarities on IV curve and Shapiro steps can be described with the analytic theory derived earlier for one-junction case and extended over the array systems.

High-voltage asymmetric MXene-based on-chip micro-supercapacitors

Abstract On-chip micro-supercapacitors (MSCs) are one of the most promising devices to be integrated into micro-/nano-scale electronic devices for offering sufficient peak power and energy support. However, low operate voltage and limited energy density greatly inhibit their wider practical application. Herein, high-voltage on-chip MSCs based on Ti3C2Tx MXene as a negative electrode and activated carbon as a positive electrode are designed and are simply manufactured via a novel cutting-spraying method. Through solving the excessive polarization of MXene, a single asymmetric on-chip MSCs can deliver a potential window up to 1.6 V in neutral electrolyte (PVA/Na2SO4), and share a high areal capacitance of 7.8 mF cm−2 (a stack specific capacitance of 36.5 F cm−3) and a greatly improved energy density of 3.5 mWh cm−3 at a power density of 100 mW cm−3, which are much higher than other on-chip energy storage counterparts. Besides, MSCs show an excellent capacity retention (remaining 91.4% after 10 000 cycles). More importantly, MSCs can be easily enlarged as highly integrated array in series and/or in parallel on the silicon wafers. Evidently, this study opens up new avenues for developing high-voltage MXene-based MSCs used in on-chip electronics and portable devices.

A generalised approach to calculate various transport observables for a linear array of series and parallel quantum dots

A systematic generalised approach to find transport observables for a linear array of different quantum dot (QD) systems has been discussed, using non-equilibrium Green function (NEGF) formalism, in the presence of on-dot Coulomb interaction and inter-dot tunnelling. The equation of motion (EOM) method has been used to derive expressions for Green functions (GFs) within the simplest mean-field approximation to tackle the Coulomb correlation term. Starting from the mathematical structures of GFs for single, double and triple quantum dot systems, the expressions for GFs and transport observables have been generalised for the quantum dot systems containing N number of quantum dots in series as well as parallel linear array of dots. Further, the formulae so obtained have been used for numerical calculations of transmission probability and the I–V characteristics of linear arrays of quantum dots in series as well as parallel configuration containing up to three dots. The results show that, with the increase in number of dots in the scattering region, transmission probability and electron current decrease in series case, while both quantities increase in parallel configuration of dots. The inter-dot tunnelling leads to the splitting of transmission peaks in double QD system in series case whereas, it induces Fano effect in triple QD system in parallel configuration.

Design of an Automated Dual IPCs 240 System for Asymmetric Power Flow Compensation in an AC Electric Network

In this paper, an automated dual IPCs 240 system for asymmetric power compensation, is designed from an analytical analysis of the power flow modes through the transmission line. Then, the ACL (automatic control logic) obtained consists of serial gates arrays of standard NAND/AND and OR operators. It has been implemented within Matlab/Simulink framework, and the simulation results obtained show the feasibility and great relevance of using the dual IPCs 240 technology, in power transmission networks under normal and contingency conditions.

A class of biaxial micro/meso-scale structures for isotropic in-plane inertial sensing and actuation: design, fabrication and experiments

A micro/meso-scale monolithic architecture was designed, fabricated and tested for in-plane inertial sensing and actuation with isotropic stiffness in the sensitive plane and high frequency-ratios between the insensitive and sensitive directions. The architecture was designed to accommodate any regular polygonal shape with a proof-mass suspension made of a serial array of compliant parallelogram linkages. Structural optimization and finite element analysis were conducted to achieve high frequency ratios and a high degree of compliance in the sensitive directions, for low-g applications and in-plane sensing. Then, the elastically isotropic structure for any regular polygonal shape was modeled in the sensitive plane and validated numerically. Lame curves were introduced in the fillets to relax the stress concentration, while air-damping analysis was introduced to provide prediction of the high resistance in the insensitive out-of-plane motion. Next, the microfabrication process was devised and conducted for triangular and square structures based on the biaxial architecture. Special techniques were studied on the wafer bonding with large cavities and the adhesive influence during deep reactive-ion etching (DRIE). Finally, techniques were studied on the reflectivity adjustment of the sample surface and the in-plane biaxial motion detection of the fundamental frequencies using a uniaxial laser-sensing system. Vibration tests conducted in the micro/meso prototypes validated the isotropic biaxial sensitivity and the size effect of the high squeezed-film air damping in the insensitive direction.

3061 Retrieval Number: D1608029420/2020©BEIESP DOI: 10.35940/ijitee.D1608.029420 Journal Website: www.ijitee.org Published By: Blue Eyes Intelligence Engineering & Sciences Publication Design of Meta Material Inspired Series and Corporate Feed Network Antenna

The present techniques are in the form of open literature used to work on selected frequency that has eight and sixteen rectangular patches. The size of it has become compact. Each approach offers different advantages, depending on the required applications. An array antenna is designed and analyzed using series and corporate feed network The FR4 substrate material which is of low cost and easily available in market is used to design the array antenna. An analysis is carried out for both series and corporate feed array antenna in terms of return loss, peak gain, VSWR, directivity, and bandwidth. The antenna’s size is reduced to a very compact size using optimization techniques without degrading the performance characteristics. The design is implemented to work for the multiband applications rather than a single application. Simulation is carried out in HFSS (High Frequency Structure Simulator) software tool. The design proposed is analyzed based on the performance and then it is fabricated.

Investigation of impact of the magnetic field through Halbach array on hydrocarbon fuel

ABSTRACT The document goes over the history of attempts made to reveal the impact of the permanent magnetic field on the hydrocarbon fuels like petrol and diesel. Magnetised fuel shows significant improvement in the reduction of the harmful exhaust gases. So far, the experimentation has been done using the permanent magnets in order to apply the magnetic flux onto the fuel line supplying fuel before combustion. But this document shows the results of using a particular arrangement of permanent magnets called Halbach arrays and its effect on the exhaust of two-wheeler vehicle in terms of reduced exhaust emissions. The document also suggests the optimum value of the intensity of the magnetic field to achieve better results of lowering emissions. The document also reveals that using a chain of Halbach arrays in series has the impressive potential of reducing exhaust gases like CO by 47%, whereas the formation of NOx can be reduced up to 90%.

Energy Dispersive X-ray Spectrometry in Combination with 3D SEM Facilitates the Identification and Segmentation of Cells and Organelles

An ongoing challenge in the field of three-dimensional (3D) scanning electron microscopy (SEM) of biological materials is the identification and subsequent segmentation of datasets rich in complex information. Techniques such as serial block face SEM (SBFSEM) and array tomography produce increasingly large amounts of data and a major resource bottleneck is the amount of research time used for processing and analysing this information (Peddie and Collinson, 2014). Selective staining techniques can aid in rapid analysis by enabling researchers to threshold data based on stain intensity (Kittelmann et al., 2016), but there are a limited range of stains that can specifically target regions or organelles of interest and the technique is hampered by the inclusion of artefacts at similar greyscale thresholds. The aim of this investigation was to test if elemental analysis using energy dispersive X-ray spectrometry (EDS) could be used to identify endogenous elements and stains in biological samples and separate them from common artefacts. Array tomography and SBFSEM was used to collect 3D data of several model systems, including animal and plant tissue, prepared using standard fixation, staining and embedding techniques for electron microscopy. Array tomography and SBFSEM was used to collect BSE images and EDS maps of tissues, cells and organelles. Serial sections were cut at a thickness of 100nm and collected onto carbon coated Kapton tape for array tomography. Blocks of resin embedded samples were serially sectioned using SBFSEM at a thickness of 100-150nm. EDS was used to generate element-based maps, which were used as masks and applied to 3D datasets. EDS maps enabled fast identification of regions of interest, helped to remove imaging artefacts and enabled rapid volumetric and quantitative analysis compared to the equivalent manual segmentation.

Deep learning-based production assists water quality warning system for reverse osmosis plants

Abstract Classifying water quality irregularities in reverse osmosis (RO) production plants requires suitable systems to provide intelligent warnings to the operators or supervisors who are engaged in executing corrective procedures applicable to production. The suggested deep learning methods are of utmost importance to identify at once variations in water quality irregularities in plants through competent classification methods, thereby enabling a reduction of burden for operators. In this paper, two types of LSTM-CNN based classification techniques are suggested to classify water quality features temporally into grades based on corrective actions that classify irregularity conditions of water quality on the basis of corrections. Distinct control methods are used for experiments to find water quality irregularities from variables, namely, pH, TDS, ORP, and EC, which aim to assist the production line. This proposed method enables automatic diagnosis and warning systems about water quality in RO plants. For classification, LSTM-CNN was trained with data recorded from eight plants of west and north parts of Chennai region. This research is meant to demonstrate particularly the top-level classification job for quality alerts. The features obtained from 4,096 time series array data using LSTM-CNNs achieved sensitivity to 97% and accuracy to 98%.

Body Wave Generation for Anguilliform Locomotion Using a Fiber-Reinforced Soft Fluidic Elastomer Actuator Array Toward the Development of the Eel-Inspired Underwater Soft Robot.

In the field of marine biology-inspired robotics, anguilliform locomotion, as one of the most common underwater propulsion types, has been widely studied and implemented in many robot prototypes. Most of these robots consisted of rigid parts, and they were able to generate smooth sine waves along the robot body using a great number of rigid segments, electric motors, and complicated control. To simplify the robot structures and improve body compliance, anguilliform robots with a full soft body are highly desirable for better biomimicry. In this article, we propose a serial soft-actuator array consisting of four fiber-reinforced, bidirectionally bending, fluidic elastomer actuators (FEAs) to achieve the generation of anguilliform body waves. The FEA is fabricated using the typical soft lithography method with dual-chamber configuration and fiber reinforcement. The bending performance of the single FEA in free space with static loads was measured and compared with the three-dimensional simulation results using the finite element method. After that, the FEA array was assembled using the through-chamber tube connection and tested in water to investigate the bending performance with dynamic loads. Finally, with coordinated control of each segment, this FEA array achieved the generation of anguilliform body waves with different frequencies and amplitudes, which unveils a novel and promising approach to develop an anguilliform underwater robot. By attaching this FEA array to a miniaturized stand-alone station for control and actuation, an untethered swimming robot was built and successfully propelled by the FEA array, which demonstrates the capabilities and potentials of this soft and slender robot body design.

Machine learning and asset allocation

AbstractInvestors have access to a large array of structured and unstructured data. We consider how these data can be incorporated into financial decisions through the lens of the canonical asset allocation decision. We characterize investor preference for simplicity in models of the data used in the asset allocation decision. The simplicity parameters then guide asset allocation along with the usual risk aversion parameter. We use three distinct and diverse macroeconomic data sets to implement the model to forecast equity returns (the equity risk premium). The data sets we use are (a) price‐dividend ratios, (b) an array of macroeconomic series, and (c) text data from the Federal Reserve's Federal Open Market Committee (FOMC) meetings.

Arrays of Annular Antennas With SINIS Bolometers

For improving the dynamic range and sensitivity at high power load, we have integrated superconductor-insulator-normal metal-insulator-superconductor (SINIS) bolometers with a frequency selective surface (FSS)-based distributed absorber formed by a series and parallel array consisting of 25 annular antenna elements, each containing two SINIS bolometers. By using a design with 50 bolometers, we reduce incident power load on each bolometer, increase sensitivity and saturation power which is important for ground-based and balloon-borne telescopes with high background power loads. Our main detector pixel is optimized for a frequency band centered at 345GHz. The detectors are matched to incoming telescope beam by a back-to-back horn with a back reflector. Such a configuration improves both the efficiency and the bandwidth of the receiver. Measured voltage responsivity approaches 210(9) VW with an amplifier-limited voltage noise of 20nVHz(12), which corresponds to a NEP 10(-17) WHz(12). The linear voltage response for incoming power is observed for absorbed power of about 5 pW. The current responsivity for parallel array is 210(4) AW and the shot noise limited intrinsic noise equivalent power is NEP 510(-18)WHz(12). The noise equivalent temperature difference is NETD 100 KHz(12) at 2.7-K background radiation temperature.

Oscillatory Regimes in a 1D Josephson Junction Array with a Nonlocal Delayed Coupling

We have numerically investigated a series array of electromagnetically coupled Josephson junctions considering the coupling delay. In the general case of a nonzero delay, we have derived equations for the slow and fast phases in the low-frequency approximation. We have studied the regimes of oscillations of a Josephson junction array for different positions of the bias point on the current–voltage characteristics (including its reverse branch). Similar analysis has been performed for systems of equations without coupling delay and for an arbitrary bias current. Several regimes of steady-state oscillations have been detected, i.e. synchronous oscillations, traveling wave regime, regime of partial switching-off of junctions, and chimera states.

Flux-Driven Josephson Traveling-Wave Parametric Amplifier

We have developed a concept for a traveling-wave parametric amplifier driven by a magnetic flux wave. The circuit consists of a serial array of symmetric dc SQUIDs coupled inductively to a separate superconducting LC transmission line carrying the pump microwave; thereby the signal and pump are applied to different ports. The proposed three-wave-mixing amplifier includes, firstly, an adjustable phase velocity of the signal (idler) wave and hence good phase matching yielding large gain in a wide frequency range and, secondly, overcoming of the pump depletion problem. The experimental parameters and characteristics of this amplifier have been evaluated and show promise for applications in quantum-information single-photon circuits.